1. Light speed skipping. A main feature of the previous movie was the lady general using light speed to break apart the big ship sacrificing herself.
A) that annoyed me as then just about any minor junk ship with a light speed capable drive could take out the biggest star destroyer, so why now suddenly, and never again. Why can't the Rebellion kit out a few fighters with droids or remote controls to just light speed into the enemy and destroy them?
b) Secondly when they skipped repeatedly into lightspeed they always ended up on what was clearly a planet, with space being so vast that is unlikely and stupid. Also if lightspeed on a ship crashes apart enemy ships why could they suddenly safely lightspeed though solid objects? It was a visually appealing scene but just terrible at breaking their own rules and insulting the audience.
2. The force could never magically heal anyone. Not even Yoda had that power. Now suddenly Rey who is barely trained can heal? Whatever.
3. Palpatine's lightning that can disable only specific enemy ships that he can't even see with precise targeting around his own armada was a stretch, and then 2 seconds later he can't bend his lightning around a lightsaber or two. Stupid.
4. Ben's sudden ability to bring Rey back to life, again with what, healing? Life transfer? No clear explanation and unnecessary plot twist.
5. I could go on but you get the idea. They change their own rules so often, or have unexplained new abilities that are very temporary and only help them get out of a writing hole they got themselves into that its just dumb.
Then not a magic rule break but her claiming the name skywalker at the end was just bad. She is a Palpatine. You can't change your genetics, and if she wants to remain on the good side then how will others feel later when they find out who she really is. The Jedi are supposed to rely on honesty, so own your name, and show by your deeds which side you are on. That whole nostalgic final scene at Luke's could have been left out.